Composition for thin walled molded parts

ABSTRACT

A polymer composition comprising an organic polymer and a mica containing effect pigment, e.g., a pearlescent pigment comprising mica, well suited for producing molded articles, in particular, for molding articles comprising thin sections and or delicate features, such as a hollow interior defined by a thin wall or structural features susceptible to tear or other damage and the like, is provided as are a method for preparing molded articles comprising the polymer composition and articles comprising the polymer composition, including, for example, an article used to deliver a medical or personal care component such as a tampon applicator, and a method for preparing molded articles comprising the polymer composition. Optionally, articles of the present disclosure have a varying translucency or opacity about a dimension of the article.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/341,769, filed May 26, 2016, the entirety of which areincorporated by reference herein.

BACKGROUND

A polymer composition comprising an organic polymer and a micacontaining effect pigment, e.g., a pearlescent pigment comprising mica,well suited for producing molded articles, in particular, for moldingarticles comprising thin sections and or delicate features, such as ahollow interior defined by a thin wall or structural featuressusceptible to tear or other damage and the like, is provided as are amethod for preparing molded articles comprising the polymer compositionand articles comprising the polymer composition, including, for example,an article used to deliver a medical or personal care component, e.g.,in one particular embodiment a tampon applicator, and a method forpreparing molded articles comprising the polymer composition.

Polymer compositions are routinely molded into articles and parts ofarticles in common daily use. Such polymer compositions must provide thearticle with desired physical features, e.g., the desired degree ofphysical strength, stiffness or flexibility, transparency or opacity,etc., the desired aesthetic features, e.g., color, surface quality,other visual effects etc., and must be capable of producing an articlewith the desired size and shape, e.g., it must be able to form a finalarticle with the desired thickness and design features which may includesharp angles, a degree of curvature, finely defined surfaces orappendages and the like.

Numerous applications require a product that possesses both highlyfunctional properties in conjunction with highly aesthetic properties.This is especially true with consumer products, where the consumer isnot only concerned with how well the particular product functions, butalso how the product looks and feels. For example, many personal care ofhome care items that contact skin or other sensitive surfaces areas,often need to be soft, flexible, and/or lubricious in order to avoiddiscomfort, scratching, abrasion etc.

U.S. Pat. No. 8,551,034 discloses a lubricious polymeric compositioncomprising a polymer and one or more lubricants, and a method for makingan article from the lubricious polymeric composition. Articles formedfrom the lubricious polymeric composition possess enhanced softness,flexibility and lubricity. Useful lubricants include fatty acid amidessuch as erucamide, oleamide, stearamide, stearyl erucamide,bis-erucamide, metallic stearate, ethylene bis stearamide, ethylene bisoleamide, etc., fatty acid glycerol esters, fatty acid salts, ethylenemethyl acrylate copolymer, polytetrafluoroethylene, long chainhydroxyamines, alkane sulfonate salts, silanes, siloxanes and the like.Excellent results were obtained when fatty acid lubricants such aserucamide, stearamides and the like were employed.

U.S. Pat. No. 8,551,034 also discloses the use of pigments, includingpearlescent pigments, in the composition, in concentrations of from 0.01wt. % to 5 wt. %, preferably 0.2 wt. % to 2 wt. %, and more preferably0.5 wt. % to 1.2 wt. % based on the total weight of the polymericcomposition. The only teaching related to useful pearlescent pigmentconcentrations is found in polymeric compositions comprising about 98wt. % to about 99 wt. % LDPE, about 0.6 wt. % mica (pearlescentpigment), about 0.5 wt. % titanium dioxide, about 0.25 wt. % erucamide,and less than about 0.01 wt. % colorant, which was also exemplified inthe production of a tampon applicator barrel; and another polymericcomposition comprising about 92 wt. % to about 93 wt. HDPE, about 5 wt.% LDPE, about 0.9 wt. % mica (pearlescent pigment), about 0.75 wt. %titanium dioxide, about 0.37 wt. % erucamide, and less than about 0.01wt. % colorant, which was also exemplified in a tampon applicatorplunger.

U.S. Pat. No. 7,226,436 discloses a multi-layered tampon applicatorwherein at least one of the ‘inner’ layers is modified for improvedvisual/aesthetic properties, improved surface characteristics, and/orimproved perception of insertion comfort. To provide opticalenhancements, one of the layers may be a coating composition wherein oneor more optical components are added to the resin and/or wax to impartaesthetic properties. Such components may include, e.g., mica,TiO₂-coated mica, iron oxide coated mica, bismuth oxychloride,holographic material, pearlescence material, reflective material,glitter, metallic effect pigment, interference pigment, liquid crystaleffect material, or any combinations thereof. Preferred opticalcomponents are mica, TiO₂-coated mica, iron oxide coated mica andbismuth oxychloride. The use of TiO₂-coated mica having a particle sizeof about 2 microns to about 150 microns at 1 wt. % to about 60 wt. %,and TiO₂-coated mica having a particle size of about 2 microns to about10 microns at about 2 wt. % to about 20 wt. %, and more preferably about5 wt. % to about 15 wt. % in the coating is disclosed.

U.S. Pat. No. 9,192,522 discloses a tampon applicator assembly having anapplicator barrel with an insertion tip and may be provided with atapered insertion tip. A shaped pledget can be housed in the applicatorbarrel, which provides support to the petals. The pledget has awithdrawal element 51 such as one or more strings. The strings can beknotted, crimped, and/or the withdrawal element can be at leastpartially braided. For example, a tampon assembly comprising a barrelregion having a plastic tubular wall having a plurality of discretepetals, separated from each other by a plurality of cuts extending alongthe barrel region that form a break of material through said tubularwall, that define a tapered shaped insertion tip region, and a taperedpledget having an end region that has been compressed to form a taperedinsertion tip contacting and supporting at least the base regions of thepetals. In one embodiment the barrel is formed from polyethylene, e.g.,low-density polyethylene (LDPE). In another embodiment the barrel isfrom LDPE and a thermoplastic elastomer (TPE). The TPE may be a blockco-polymer comprising styrene, butadiene or isoprene and styrene orother TPEs such as polyurethane elastomers and others.

U.S. Pat. No. 8,337,378 discloses a tampon applicator comprising aplunger and a barrel having a wall forming a tube with a center axistherethrough and with a hollow interior volume, which barrel comprisesfour distinct sections, namely a finger grip section, a reverse tapersection, a main body section, and a tapered insertion tip section,wherein the reverse taper section is tapered towards the fingergripsection, and the main body section is tapered in an opposite directiontowards the insertion tip section. A maximum diameter is formed wherethe reverse taper section and main body section meet on the barrel andprovides a sensory indicator to the user to alert the user when theapplicator has been inserted to the proper depth.

Various tampon applicator and tampon barrel architectures capable ofbeing molded from polymer compositions are known, some examples of whichcan be found in U.S. D 515,212; U.S. D 572,362; U.S. D 579,113; U.S. D612,940; U.S. D 492033; and U.S. D 511832.

Many polymer compositions capable of providing functional and aestheticproperties desired for certain products are not sufficiently compatiblewith some of the molding processes used in their production. Forexample, many polymer compositions, known to produce products withcertain optical properties, such as those comprising pearlescent micapigments, can generate an unacceptable amount of products that are torn,ruptured or otherwise damaged during certain molding processes,especially those which generate high stress on the polymer duringprocessing. This is especially problematic when producing articles withvery thin sections or certain details such as the petals of the tamponapplicator described above.

It was found that reducing the amount the amount of mica typicallypresent in such polymer molding compositions will allow one to preparetranslucent or pearlescent articles, with aesthetic properties such assoft feel, flexibility, and/or lubricity that are desirable for manyitems, including, e.g., personal care items, without generatingexcessive waste due to scrap produced during molding, even when usinghigh stress molding methods.

SUMMARY

One embodiment of the invention provides a polymer composition forpreparing a molded article, also called a polymer molding composition,comprising, based on the total weight of the polymer composition:

from about 95 to about 99.8% of an organic polymer,

from about 0.05 to 0.5%, e.g., about 0.1 to about 0.5% or 0.15 to about0.35 or 0.4% of a pearlescent pigment comprising mica,

from about 0.002 to about 0.1%, e.g., about 0.005 to about 0.07%, about0.007 to about 0.05, of a colorant other than a pearlescent pigmentcomprising mica,

from about 0.05 to about 1.0% of a lubricant comprising a fatty acidamide,

and from 0 to 4.8%, e.g., about 0.05 to about 4.8% other additives.

The pearlescent pigment comprising mica typically comprises a micaparticle coated with one or more layers, wherein at least one layercomprises titanium dioxide.

Colorants other than the pearlescent pigment comprising mica can be oneof a wide variety of pigments or dyes, but in many embodiments pigmentsare preferred, including white pigments, including e.g., inorganic whitepigments such as titanium dioxide, effects pigments, such as otherpearlescent pigments, black pigments including composite back pigmentsand carbon black, and organic and inorganic pigments of various colorsother than black or white. Combinations of more than one such colorantare often used.

The other additives, when present, typically comprise one or moreadditive selected from the group consisting of plasticizers,compatibilizers, flow modifiers, antioxidants, antistatic agents,fillers, reinforcements, surfactants, light/UV stabilizers, thermalstabilizers, impact modifiers, processing aids, other lubricants, flameretardants, biocides, antiozonants, blowing agents and anti-foamingagents, however, any polymer additive commonly used in the art may bepresent in the polymer molding composition.

The organic polymer may comprise a thermoplastic, elastomeric orthermoset polymer, and generally comprises a thermoplastic and/or anelastomeric polymer, and often comprises a thermoplastic polymer. Inmany embodiments the organic polymer comprises, for example, apolyolefin polymer or copolymer, polyester, polyamide, polystyrene,polyvinyl chloride, polyacrylate, polymethacrylate, polyvinyl alcohol,polylactic acid, or a moldable starch, for example, polyethylene, linearlow density polyethylene, low density polyethylene, high densitypolyethylene, near low density polyethylene, polypropylene, copolymerscomprised of ethylene, styrene, isoprene or butadiene monomers, and insome embodiments the organic polymer comprises low density polyethylene,high density polyethylene or a mixture of low density polyethylene andhigh density polyethylene. More than one organic polymer may be presentin any composition of the present invention.

The lubricant comprises a fatty acid amide, such as erucamide, oleamide,stearamide, stearyl erucamide, bis-erucamide, ethylene bis stearamide,ethylene bis oleamide, etc., for example, erucamide, oleamide,stearamide, stearyl erucamide or bis-erucamide. In some embodimentsother lubricants are also be present, such as one or more of thelubricants found, for example, in U.S. Pat. No. 8,551,034 cited above.

Another broad embodiment provides a process for preparing the abovepolymer compositions. While one can prepare the composition by mixingtogether the various polymers, pigments, lubricants etc., in the desiredamounts according to any standard processing technique, it is oftendesirable to first prepare a color concentrate (also referred to as acarrier) comprising the pearlescent pigment comprising mica, colorantother than pearlescent pigments comprising mica, the lubricant and otheroptional additives and a smaller amount of polymer than is present inthe inventive polymer composition, and then compounding the concentratewith a base polymer.

For example, one embodiment provides a process for producing the polymercomposition above, i.e., polymer molding composition, which processcomprises compounding a mixture comprising from about 1 to about 10 wt%, e.g., from about 2 to about 6 wt %, of a color concentrate and from90 to 99 wt %, e.g., 94 to 98 wt %, of a base polymer wherein the basepolymer comprises an organic polymer and the color concentratecomprises, based on the total weight of the polymer composition:

from about 50 to about 95% of an organic polymer,

from about 0.5 to about 10%, e.g., about 4 to about 8% of a pearlescentpigment comprising mica,

from about 0.02 to about 1.3%, e.g., about 0.3 to about 1.0 of acolorant other than a pearlescent pigment comprising mica

from about 0.5 to about 10% e.g., about 1.5 to about 3.0% of a lubricantcomprising a fatty acid amide

and from 0 to about 40% other additives.

One must select the appropriate let down ratio, i.e., weight percent(wt. %) of color concentrate compounded into the base polymer in orderto prepare a polymer molding composition according to the presentinvention. For example, using 10 wt. % of a color concentrate comprising10 wt. % of a pearlescent pigment comprising mica results in a polymercomposition of comprising 1 wt. % of the pearlescent pigment comprisingmica, which is well outside the ranges of the present invention, whereasthe same concentrate at a 2 wt. % let down results in a compositionhaving 0.2 wt. % of the pearlescent pigment, which is within the rangeof the inventive composition.

One particular embodiment of the invention provides the above colorconcentrate.

The organic polymer of the color concentrate and the base polymercomprise one or more of the polymers cited above for the polymer moldingcomposition. The polymer or mixture of polymers in the color concentratemay be the same as, or different from, the polymer or mixture ofpolymers of the base polymer.

The pearlescent pigment comprising mica, colorant other than apearlescent pigment comprising mica, lubricant comprising a fatty acidamide, and other additives of the color concentrate are those describedabove for the molding composition.

The base polymer may also comprise one or more of these components, forexample pearlescent pigment, colorants, lubricants, processing aids,stabilizers etc., but the base polymer would comprise the pearlescentpigment comprising mica or colorant other than a pearlescent pigmentcomprising mica at a much lower level than found in the concentrate, ifat all. In many embodiments the base polymer does not comprise eitherthe pearlescent pigment or other colorant. The base polymer may alsocomprise a lubricant, which may or may not be the same lubricant of thecolor concentrate, in some embodiments the base polymer does notcomprise a lubricant.

Compounding refers to a process wherein an intimate mixture ofcomponents is created. In the present case, this may be any known methodof compounding, including high shear mixing, blending the components,typically in a molten state, at elevated temperature, extrusion, etc. Inone particular process, the compounding step is integrated with theprocess of molding an article, for example, a mixture of the colorconcentrate and base polymer may be added to an extruder, extruded toprepare an intimate mixture of the components and then directly injectedinto a mold. In other embodiments, the polymer molding composition isprepared separately from the molding step, e.g., it may be extruded andpelletized,

Another broad embodiment of the invention provides a molded articlecomprising the polymer composition above, i.e., polymer moldingcomposition, a process for preparing such an article, and an improvedprocess for reducing scrap when molding articles under high stressconditions. In many embodiments the article comprises certain opticaleffects, e.g., pearlescence, translucency etc. In particular embodimentsthe article is variably translucent, meaning that the degree oftranslucence varies in different sections of the article. The articlemay also vary in color, e.g., the hue, depth, or lightness of the colormay vary indifferent sections of the article.

The article of the invention may comprise one thickness or variousthicknesses. Many embodiments provide a molded article wherein at leasta portion of the article has a thickness ranging from about 0.002 mm toabout 2.0 mm, e.g., about 0.05 mm to about 1 mm, or about 0.1 mm toabout 0.9 mm. Some embodiments provide an article wherein the entirearticle comprising the polymer composition of the invention is 2 mm orless than 2 mm thick.

In particular embodiments the molded article comprises a hollow interiorvolume typically accessible through one or more openings, which hollowinterior volume is at least partially defined by one or more wallscomprising the polymer molding composition. For example, the article maycomprise a generally tubular void or cup shaped void defined by at leastone curved wall comprising the polymer molding composition, which wallhas one or more thicknesses in of from about 0.002 mm to about 2.0 mm,from about 0.05 mm to about 1 mm, or from about 0.1 mm to about 0.9 mm.

One particular embodiment provides a device, or part of a device, whichdevice is a delivery apparatus for a medical, personal care, home careor veterinary item, for example, a device comprising a barrel and aplunger wherein the barrel comprises an interior hollow volume fromwhich the medical, personal care, home care or veterinary item isdelivered, wherein the barrel and/or plunger comprises the polymermolding composition of the invention. In one particular exemplaryembodiment of the invention the device is a tampon applicator, but otherdevices comprising the present polymer composition are also preparedfrom the present polymer composition.

The present invention is particularly useful in molding an articlecomprising structural features associated with causing rupture (i.e.,fracturing and/or splitting) of the article during molding. For example,a device comprising at least two sections having structural featuresdifferent than the other, and wherein at least one section comprises oneor more features associated with causing rupture of the article duringmolding, such as tapering to a thickness of less than 1 mm, a slit, anangle of 90 degrees or less especially in a section less than 2 mm orless than 1 mm thick, a narrow joint between two wider sections, or asection that is placed under higher physical stress during processingthan other sections of the article. For example, in one embodiment thepolymer molding composition is used to prepare the barrel of a tamponapplicator comprising a hollow interior volume defined by a curved walland two ends, wherein the barrel tapers toward one end having anopening, which end may also comprise petals, e.g., sections separated byslits in the wall, typically curved in a manner to narrow or temporarilyclose the barrel, which will open under pressure to allow for exit of anabsorbent pledget.

The articles of the invention may be formed by many known moldingprocesses including, e.g., injection molding or compression molding thepresent polymer molding composition.

One embodiment provides a compression molding process comprising atleast partially filling an open mold cavity with the polymer compositionof the invention, which in many embodiments is formed according to theletdown process above, and then inserting a second mold member into thepolymer composition in the open mold to define a space between the openmold cavity and the second mold member and to force the polymercomposition to fill said space to form an article of the invention. Thepolymer composition may be molten or softened to a point where it can beforced to fill the space between the open mold cavity and the secondmold element either before or during the molding process, and either orboth of the mold cavity or second mold element may be heated at atemperature to melt or soften the polymer composition.

Forming an article by molding the polymer composition of the inventionusing the above injection molding or compression molding processes hasbeen found to greatly reduce the amount of scrap from torn, ruptured orotherwise malformed articles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a tampon applicator according to thepresent disclosure.

FIG. 2 is a diagrammatic view of a tampon applicator according to thepresent disclosure.

FIG. 3 is a diagrammatic view of a tampon applicator according to thepresent disclosure.

FIG. 4 is a diagrammatic view of a tampon applicator according to thepresent disclosure.

FIG. 4a is a diagrammatic sectional view of a tampon applicatoraccording to the present disclosure.

FIG. 5 is a diagrammatic sectional view of a tampon applicator accordingto the present disclosure.

DETAILED DESCRIPTION

The polymer composition of the present invention can be used to moldarticles having a variety of functional and aesthetic properties and canbe used to prepare articles useful in applications with particularrequirements, such as personal care applications, where a soft orlubricious feel is a necessity and where a consistency in overallappearance contributes greatly to consumer confidence. In applicationssuch as these, certain properties that may be considered ancillary oraesthetic in other applications assume a more primary importance as itrelates to the present disclosure. The present polymer compositionreadily provides such articles with excellent structural, color, andother optical properties, but also may be used to form articles withhigh degrees of softness, flexibility and/or lubricity.

The polymer composition of the invention comprises one or more organicpolymers typically selected from common synthetic polymers or naturallyoccurring materials such as a polyolefin polymer or copolymer,polyester, polyamide, polystyrene, polyvinyl chloride, polyacrylate,polymethacrylate, polyvinyl alcohol, polylactic acid or moldable starch.The polymers may be thermoplastic, elastomeric or thermoset polymers,but typically comprise a thermoplastic and/or an elastomeric polymer.Most often the polymer will comprise a thermoplastic polymer or a blendof a thermoplastic and elastomeric polymer.

For example, the polymer often comprises a polyethylene, low densitypolyethylene, high density polyethylene, linear low densitypolyethylene, polypropylene, or a copolymer comprised of ethylene,styrene, isoprene or butadiene monomers. In many embodiments the organicpolymer comprises low density polyethylene, high density polyethylene ora mixture of low density polyethylene and high density polyethylene.

In some embodiments, the organic polymer comprises a blend of apolyethylene, e.g., low-density polyethylene and a thermoplasticelastomer. For example, the organic polymer may comprise a blend ofabout 50 wt. % to about 90 wt. %, e.g., about 80 wt. %, low-densitypolyethylene and about 50 wt. % to about 10 wt. %, e.g., about 20 wt. %,thermoplastic elastomer, based on a total weight of the composition. Oneuseful thermoplastic elastomer is a tri-block (terpolymer), having anA-B-A configuration of monomers, in which monomer B is not the same asmonomer A. Typically the blocks comprise styrene, butadiene, or isoprenemonomers. Other classes of useful thermoplastic elastomers include, forexample, thermoplastic polyurethane elastomers.

A variety of additives are common in polymer compositions includedprocessing aids, stabilizers, colorants, etc. . . . . Any suitableadditive common in the field may also be used in the presentcomposition, including for example, plasticizers, compatibilizers, flowmodifiers, antioxidants, antistatic agents, fillers, reinforcements,surfactants, light/UV stabilizers, thermal stabilizers, impactmodifiers, processing aids, other lubricants, flame retardants,biocides, antiozonants, blowing agents, anti-foaming agents and thelike.

In order to possess or maintain the proper softness and/or lubricityneeded in many of the articles of the invention, the compositioncontains at least 0.05 wt. % of a lubricant, which lubricant comprises afatty acid amide. Typically, the lubricant comprises erucamide,oleamide, stearamide, stearyl erucamide, bis-erucamide, ethylene bisstearamide, ethylene bis oleamide, etc., for example, erucamide,oleamide, stearamide, stearyl erucamide or bis-erucamide.

Other optional lubricants may also be present in addition to the fattyamide, for example, calcium stearate, glycerol monostearate, magnesiumstearate, calcium stearate, zinc stearate, aluminum di-stearate, fattyacid glycerol esters, calcium soaps of montanic acids, triglycerylesters of hydroxy saturated fatty acids, ethylene methyl acrylatecopolymer, polytetrafluoroethylene, micronized PTFE, mineral oil, C14-18alkyl di(2-hydroxyethylamine), sodium alkane sulfonates, dimethicone andother polydimethyl siloxanes, t-butyldiphenylchlorosilane, other polararomatic and aliphatic silanes such as chloromethyldimethylchlorosilane,epoxylated soybean oil, oxidized polyethylene wax, K-Y jelly and/orglycerol.

One skilled in the art will be able to adjust the lubricity of anarticle formed from the present polymer molding composition by varyingthe total amount of lubricant present in the composition.

The composition comprises a pearlescent pigment comprising mica whichserves to provide a variety or optical properties to the composition,and colorants, e.g., pigments and dyes, for example organic andinorganic pigments other than the pearlescent pigment comprising mica.The pearlescent pigment comprising mica typically comprises a micaparticle, such as a mica platelet or flake, which is coated with one ormore layers of other materials, e.g., metal oxides, silicas, etc. . . .

The pearlescent pigments themselves are particles, often in a generallyplatelet or flake form, which are typically not of a uniform shape. U.S.Pat. No. 7,226,436 discloses TiO2-coated mica having a particle size ofabout 2 microns to about 150 microns, and TiO2-coated mica having aparticle size of about 2 microns to about 10 microns. Pearlescentpigments are also known that are defined by having a diameter and adefined thickness in the range of plus or minus 10%, of the averagethickness. For example, the particles may be flakes having a thicknessof from 20 to 2000 nm, e.g., from 100 to 350 nm and a diameter of about1-60 microns, e.g., about 5-40 microns.

In many embodiments of the invention, the pearlescent pigment comprisingmica comprises a mica, particle, flake or platelet coated by one or morelayers, wherein at least one of these coating layers comprises titaniumdioxide. Generally, the pigment particle fits within the one of theabove dimension ranges. A variety of such pigments are commerciallyavailable, including, e.g., CI Pigment White 20, also known as PW 20.

In addition to providing the composition with a nacreous sheen, thepearlescent pigment also has the ability to affect the opacity of thecomposition and contribute to varying degrees of translucency. Oneparticular optical effect that can be imparted to an article producedusing the polymer composition of the invention is variable translucence.That is, an article can be formed from the composition where a portionof the article is more translucent than another portion of the article.As used herein. the term “same color” means colors having the same huebut which can differ in intensity. such as lightness and darkness. Asused herein. the term “visually perceptible” to a consumer is meant thata human viewer can visually discern a difference with the unaided eye(excepting standard corrective lenses adapted to compensate fornearsightedness. farsightedness. or astigmatism. or other correctedvision) in lighting at least equal to the illumination of a standardone-hundred-watt incandescent white light at a distance of 0.25 meter.As used herein. the term “translucent” means that a consumer canvisually perceive what is on the opposite side of the transparent objector thing. The term translucent also includes transparent regions. Asused herein. the term “opaque” means that a consumer cannot visuallyperceive what is on the opposite side of the opaque object or thing.

In some embodiments, translucency is a gradient along a dimension of thearticle (i.e. such as the length, width, or a radial dimension). In someembodiments, the insertion tip region has a translucency of up to 100%(i.e. is not opaque), is up to 75%, is up to 50%, is up to 25%, is up to10% translucent, where such translucent portion is at least at a singledimensional location along the insertion tip. For instance, in someembodiments, the highest translucency portion of the insertion tip is atthe tip end. In other embodiments, the insertion tip has a gradient oftranslucency/opacity along the length of the insertion tip. In some suchembodiments, the insertion tip end (also referred to as forward end) 36has the greatest translucency, while the end of the insertion tip regionadjacent the barrel region has the lowest translucency of the tip region(or said differently, the highest opacity).

In other embodiments, the barrel region has a translucency of up to100%, up to 75%, up to 50%, up to 25%, up to 10%, or having 0%translucency. In some embodiments, the barrel region has a gradient oftranslucency/opacity along the length of the barrel region. In some suchembodiments the gradient favors translucency on either or both of theextremes of the barrel region (i.e. adjacent (a) the insertion tip, or(b) depending on the embodiment, adjacent the reverse taper region orthe grip region).

In other embodiments having a reverse taper region (as with, forexample, at least FIGS. 5 and 5A), the reverse taper region has atranslucency of up to 100%, up to 75%, up to 50%, up to 25%, up to 10%,or having 0% translucency. In some embodiments, the reverse taper regionhas a gradient of translucency/opacity along the length of the reversetaper region. In some such embodiments the gradient favors translucencyon either or both of the extremes of the reverse region (i.e. adjacent(a) the barrel region, or (b) adjacent the grip region).

In other embodiments, the grip region has a translucency of up to 100%,up to 75%, up to 50%, up to 25%, up to 10%, or having 0% translucency.In some embodiments, the grip region has a gradient oftranslucency/opacity along the length of the grip region. In some suchembodiments the gradient favors translucency on either or both of theextremes of the grip region (i.e. adjacent (a) the barrel region, or (b)at the distal end of the grip region).

In other embodiments, the plunger has a translucency of up to 100%, upto 75%, up to 50%, up to 25%, up to 10%, or having 0% translucency. Insome embodiments, the plunger has a gradient of translucency/opacityalong the length of the plunger. In some such embodiments the gradientfavors translucency on either or both of the extremes of the plunger(i.e. (a) the plunger end engaging the pledget, or (b) the rearward endof the plunger opposite the pledget engaging end).

In some embodiments having a two-piece plunger (as in FIG. 5), either orboth plungers have a translucency as described in the precedingparagraph. In further embodiments, the two plungers have a translucency(or opacity) that is different in an initial, disconnected state, and anin-use, connected state. In some such embodiments, the translucency oropacity is further distinct with regard to the connection region,particularly in the in-used, connected state.

Translucency (or opacity) can be influenced by the amount of micacontaining pearlescent pigment used, the amount of other colorantspresent and the ratio of pearlescent pigment comprising mica to othercolorant, etc. Other factors such as the organic polymer, the shape ofthe article, the thickness of the article or difference in thethicknesses of article comprising more than one thickness can play arole. It is also possible that the stress on various sections of thearticle, e.g., a section stressed by undue curvature, or the stressesexperienced by the composition during the molding process may play arole in the relative amounts of translucence.

The present polymer composition comprises 0.5 wt % or less, of thepearlescent pigment comprising mica, e.g., less than 0.5 wt % such as0.4 wt % or less, which is lower than the level typically encountered inother similar compositions, e.g., U.S. Pat. No. 8,551,034 or 7,226,436.Without being bound onto theory, it appears that it is this lower levelof mica containing pearlescent pigment that allow one to preparerelatively thin articles using certain economically favorable but highstress molding techniques, such as forced compression molding, withoutexcessive scrap.

The colorants other than the pearlescent pigment comprising mica can bealmost any other colorant, such as dyes, inorganic pigments or organicpigments, provided that they are compatible with the polymer, processingtechnique, and end use. For example, certain colorants such as dyes mayleach out of the polymer on storage or in use. Such colorants would begenerally unsuitable in an article that contacts the skin or delivers amedical or personal care item. In certain embodiments the only micacontaining pigment present in the polymer composition is the pearlescentpigment comprising mica.

Useful colorants include, e.g., white pigments and opacifiers, such astitanium dioxide and other inorganic white pigments. Black pigmentsincluding carbon blacks and composite blacks may be used as well as awide variety of known yellow, orange, red, violet, green, blue, pink andother colored pigments and dyes. Surprisingly, it has been found that,without modulating such colorants, the opacity can be reduced, or saiddifferently, the translucency increased.

Examples of organic pigments include azo, azomethine, methine,anthraquinone, phthalocyanine, perinone, perylene, diketopyrrolopyrrole,thioindigo, dioxazine, iminoisoindolinone, quinacridone,benzimidazolone, flavanthrone, indanthrone, anthrapyrimidine andquinophthalone pigments, or a mixture or solid solution thereof.Suitable inorganic pigments include, for example, metal oxides, mixedmetal oxides, and metal sulfides. A small selection of specific pigmentsinclude ultramarine blue, cobalt blue, manganese blue, cobalt green,cerium sulfide, cadmium sulfide, cadmium sulfoselenides, zinc ferrite,bismuth vanadate, iron oxide, red iron oxide, orange iron oxide, whitezinc sulfide, aluminum powder, bronze powder, phthalocyanine green,phthalocyanine blue, phthalocyanine red, diarylide yellow, quinacridonered, rhodamine red, lithol rubine red, napthol red, neozapon red,carbizole violet, barium sulfate and the like.

The selection of appropriate colorant is within the skill of the averagepractitioner. Often, more than one colorant is used to generate thedesired color.

Some of the advantages of the present invention can be illustrated in aspecific embodiment. For example, a tampon applicator of FIG. 1comprises a barrel and a plunger. A pledget comprising an absorbentmaterial is held within the barrel until ejection by the plunger. Asofter applicator barrel is more comfortable and is a desirable featureof a tampon applicator in order to provide improved ease of insertion.

Consumers are interested in tampon applicators that are soft yetresilient (i.e. resist forces encountered when inserting into the bodysuch that the product is insertable and doesn't merely collapse ordeform thereby rendering insertion a failure or difficult), comfortableto insert, with a suitable ejection force. Translucency, to some degree,of a portion of the tampon applicator, if not multiple portions, isadvantageous as it enables the consumer to see the absorbent product(i.e. a tampon pledget) within the applicator such that the consumer cansee the pledget (or portions thereof such as the tip, the withdrawalelement, etc. . . . ) and understand how it is being deployed (andafterwards, confirming it has been deployed as the applicator appearsvacated). A softer applicator barrel is more comfortable and is adesirable feature of a tampon applicator in order to provide improvedease of insertion and a noticeable degree of lubricity is also oftendesired. Tampon manufacturers want applicators made of inexpensive,low-cost materials that are easy, rapid and inexpensive to manufactureat high volumes and tampons that can be assembled at high speeds withonly minor modifications.

Presently, molding compositions used in the formation of plastic tamponapplicators can deliver high quality articles, but some of thesecompositions are not fully compatible with certain economicallyadvantageous manufacturing processes. Further complicating themanufacturing issues, many successful tampon applicator designs comprisefeatures that are often difficult to form in high volume manufacturingprocesses. For example, the barrels of some tampon assemblies include adome shaped end, FIG. 1, or a tapered end for comfort and ease ofinsertion, FIG. 2, that includes a number or plurality of shaped petalsconfigured to open during ejection of the pledget. The petals areseparated from each other by a plurality of cuts extending along thebarrel region that form a break of material through said tubular wallthat are visible in FIGS. 1 and 2, which cuts can create site wheretearing during formation of the barrel.

The petals need to readily and smoothly open without undue resistanceduring ejection of the pledget from the barrel. The petals are thuspreferably soft, highly flexible and thin-walled. FIG. 4A shows aschematic diagram of a tampon assembly of the invention, wherein thepledget has a tapered end that can support at least a part of the petalsduring insertion of the applicator assembly, which allows for thinner,softer, more flexible petals.

FIGS. 4 and 4A illustrates a tampon applicator of the invention having abarrel and a plunger with a flared end, wherein the barrel has variouswidths and walls with various thicknesses, and comprises a grip region,a reverse taper region, a barrel region and an insertion tip region,wherein the insertion tip region is tapered, the main body section has amaximum diameter section that is sensually perceivable to a user toalert the user to the proper insertion depth of the applicator, and areverse taper region towards the grip region.

FIG. 5 illustrates a tampon applicator having a two-piece plunger (i.e.a first plunger segment and a second plunger segment).

The manufacturer is thus faced with the task of efficiently andeconomically preparing soft, tubular, tapered, thin-walled, lubriciousplastic parts with various widths and thicknesses, with soft, flexible,curved appendages that are formed buy cuts into a tube under a degree ofstress due to the curvature of the walls. Preparing such parts usingcertain molding processes with compositions having commonly used levelsof pearlescent pigments comprising mica, such as those used in thepresent invention, has led to an unacceptably high level of scrap due tobarrel splitting due largely to the cuts into the barrel that form thepetals, and/or the use of post-forming features onto the molded articleby compression molding (i.e. forming a tapered or flared end of the gripregion, and/or the plunger).

The use of the polymer molding composition of the invention in moldingoperations to form molded articles such as these tampon applicatorbarrels has been shown to provide high quality, smooth, soft,thin-walled, lubricious barrels with excellent aesthetic properties,while also reducing the amount of scrap due to, e.g., barrel splitting.In one example, tampon barrels comprising a tapered insertion tip withpetals as described above were prepared by molding a polymer compositionof the invention having between 0.15 wt. % and 0.33 wt % pearlescentmica containing pigment, which produced significantly less scrap thanwhen the barrels were prepared using a similar molding compositioncomprising between 1 wt. % and 1.3 wt. % of the same pearlescentpigment.

The structural advantages of using the polymer composition of theinvention molding other articles should be apparent to anyone skilled inthe art.

Other advantageous results can also be realized. For example, thepolymer composition of the invention can produce articles with variousvisual properties including high gloss, excellent color, pearlescence,translucency and variable translucency. In preparing the tampon barrelsdescribed above, for example, depending on the exact conditions andcompositions used, barrels could be prepared with a high degree ofvariable translucency, such that barrels are very translucent in thetapered tip and petals and become deeper in color and less translucentin the regions further away from the tip. However, it is possiblethrough minor variations in the polymer composition to produce a barrelwith high gloss, consistent color, and a more moderate variance intranslucency. It is also possible to produce barrels with high gloss andlittle or no translucency.

For example, a color concentrate comprising about 6.4 wt. % pigmentwhite 20 (a pearlescent pigment comprising mica), about 0.9 wt. % of amixture comprising titanium oxide and other colored pigments, about 2.8wt. % of a mixture of erucamide and a bis stearamide in a low densitypolyethylene carrier was let down at 3.5% and 3.0% into a low densitypolyethylene base polymer and the barrels as described above were moldedusing the resulting polymer compositions. Barrels prepared from the 3.0%and 3.5% letdowns were both variably translucent, the barrel producedfrom the 3.0% letdown was highly translucent at the tip, whereas thebarrel produced from the 3.5% letdown was more moderately translucent atthe tip. These samples demonstrate a gradient effect of translucency tocolor over a portion of a molded article, such as over the length of theentire applicator barrel, a portion of the applicator barrel such as theinsertion tip, the barrel region, the reverse taper region, the gripregion, and/or the plunger, such as a first plunger segment, a secondplunger segment, a portion of a plunger (or plunger segment), etc. . . .. In some embodiments, a translucency to color gradient can be furthermodified by varying the thickness (i.e. along the length) of the moldedpart.

Barrels can also be prepared from the color concentrate above at higherlet down ratios, e.g., 5%, 6%, 7%, 8% and above 8% etc., but as theletdown ratio with this particular color concentrate increases pastabout 5%, a gradual increase is scrap becomes noticeable. In alternativeembodiments, let down ratios of less than 2% are also possible.

As stated, the polymeric composition, i.e., the polymer moldingcomposition, of the invention may be formed by any suitable method knownin the art. For example, the polymeric composition can be formed bycombining the proper amount of all the components in a twin-screwextruder, and then extrude the molten mixture which can then be cut tointo pellets, but any high temperature and/or high shear method thatproduces an intimate mixture of the components can be used. However, asknown in the art and as seen above, small changes in the polymer moldingcomposition can cause noticeable changes in an article preparedtherefrom, and greater control over the formation of the polymer moldingcomposition can be obtained by letting down a color concentrate into abase polymer.

One embodiment of the invention thus provides a process for producingthe polymer molding composition, which comprises compounding a mixturecomprising from about 1 to about 10 wt. %, e.g., from about 2 to about 6wt. %, of a color concentrate and from 90 to 99 wt. %, e.g., 94 to 98wt. %, of a base polymer wherein the base polymer comprises an organicpolymer and the color concentrate comprises, based on the total weightof the polymer composition:

from about 50 to about 95% of an organic polymer,

from about 0.5 to about 10%, e.g., about 4 to about 8% of a pearlescentpigment comprising mica,

from about 0.02 to about 1.3%, e.g., about 0.3 to about 1.0 of acolorant other than a pearlescent pigment comprising mica

from about 0.5 to about 10% e.g., about 1.5 to about 3.0% of a lubricantcomprising a fatty acid amide

and from 0 to about 40% other additives.

Selecting the proper letdown ratio for a given color concentrate inorder to prepare a polymer molding composition of the inventioncomprising the required components is within the purview of one skilledin the art, i.e., a poly composition comprising from about 0.05 to 0.5%,e.g., about 0.1 to about 0.5% or 0.15 to about 0.35 or 0.4% of apearlescent pigment comprising mica, from about 0.002 to about 0.1%,e.g., about 0.005 to about 0.07%, about 0.007 to about 0.05, of acolorant other than a pearlescent pigment comprising mica, from about0.05 to about 1.0% of a lubricant comprising a fatty acid amide, andother optional additives.

The color concentrate in the aforementioned example comprises about 6.4wt. % pigment white 20 (a pearlescent pigment comprising mica), about0.9 wt. % of a mixture comprising titanium oxide and other coloredpigments, about 2.8 wt. % of a mixture of erucamide and a bis stearamidein a low density polyethylene carrier and can be let down at a ratio of2 to 6%, or 2.5 to 6% into a suitable polymer to produce a polymercomposition of the invention useful in preparing the. For thisparticular composition, the most desirable results in producing thetampon applicator barrel above were achieved at let down ratios of 2.5to 5%, and in some cases excellent results were achieved at a letdownratio of 3 to 4%. However, color composition with a differentcomposition, e.g., a different ratio of pearlescent pigment to othercolorant or the use of different pigments etc., may require a differentletdown ratio for the best results.

Barrels were prepared in a variety of colors including green, limegreen, orange, magenta, turquoise, and dark green using moldingcompositions prepared in a manner analogous to that above, but usingdifferent colorants. Other colors are within the scope of the presentdisclosure, including without limitation, shades of green, shades ofblue, shades of red, shades of purple, shades of pink, shades of white,shades of orange, and shades of yellow.

A color composition comprising larger quantity of pearlescent pigmentwould likely require a lower letdown ratio and the use of a differentbase polymer affects what the optimum level of the various componentsshould be.

Furthermore, other molded articles prepared according to the presentinvention, e.g., a bottle or other container, a delivery apparatus foran oral or other veterinary composition, a medical device etc., can havea different set of specific properties that are most desirable, andtherefore best results would likely be provided using a differentoptimal concentration, within the limits of the present disclosure, ofpolymer molding composition components and color concentrate components,and different letdown ratios. However, optimizing the present inventionin such a manner would be within the purview of one skilled in the artafter reading the present specification.

Compounding the color concentrate with the base polymer can occurthrough any known method, e.g., extrusion, high shear mixing, usingsolid colorant or carrier composition, blending of a liquefied moltenmixture of color concentrate and base polymer etc. It is also possibleto lend a liquefied or molten color concentrate with a liquefied ormolten base polymer. The compounding of the color concentrate with thebase polymer can also be integrated with the molding process, forexample, an extrusion step or other melt blending step can be integratedwith injection molding. In one embodiment, a liquefied or molten colorconcentrate and a liquefied or molten base polymer are fed into anapparatus which mixes the components and feeds the result into a mold.

The actual molding process may also employ any known method, e.g., castmolding, injection molding, compression molding, other post-processingor post-forming means, etc. The tampon barrel exemplified above, forexample, can be efficiently formed by injection molding. Anotherefficient and economical process for forming the barrel comprisespartially filling an open mold with the polymer molding composition,frequently a molten composition, and compressing the composition with asecond mold member.

Temperatures and pressures and exact processing conditions used inmolding the articles of the invention will vary. In the preparation ofthe barrels exemplified above, post-processing pressures between 200 psiand 1,000 psi, and temperatures having an upper range between 225° F.and 300° F. were often employed. To manufacture such articles viainjection molding, pressures between 11,000 psi and 14,000 psi wereused, and temperatures between 380° F. and 425° F. were employed.

Despite the polymer composition's value in forming other articles, theparticular embodiment comprising a tampon applicator, and specificallythe barrel of a tampon applicator, can be used to demonstrate manyadvantages of the invention, and more will be said about it here.

FIGS. 1 and 2 show tampon applicators of the invention comprising abarrel and a plunger that extends into the barrel at one end. The endopposite the plunger comprises the insertion tip and petals that openwhen pressed to allow the pledget to be ejected. FIG. 3 shows an endview of an insertion tip having 4 petals, Tampon applicators having 3petals are also known, and applicators having more than 4 petals areeasily envisaged (i.e. 5, 6, 7, and 8 petals). At least FIGS. 1, 2, and4 show the slits or cuts 29 that define the petals. These cuts may varyin length depending on the desired length of the petal.

One embodiment of the invention provides a tampon applicator barrelcomprising the polymer composition of the invention. In anotherembodiment, the barrel and/or the plunger comprise the polymercomposition of the invention.

FIGS. 2, 4 and 4A also illustrates a tampon applicator of the inventionwherein the barrel is tapered becoming more narrow at the insertion tip.In embodiments wherein the tampon applicator is variably translucent,the region near and/or comprising the insertion tip is typically moretranslucent than other portions of the applicator barrel, for example,the wider section of the barrel in embodiments having a tapered barrelregion. In one embodiment of the invention, the thickness of the barrelwall is the same through the barrel, but in another embodiment, as shownin FIG. 4A, the barrel wall has multiple thicknesses, and in aparticular embodiment the barrel wall, including the petals, is thinnerat or toward the ejection tip than it is at the wider portion of thebarrel.

One particular tampon applicator embodiment is illustrated in FIGS. 4and 4A which includes a plunger 12 and a barrel 20. Barrel 20 is dividedinto four sections including a grip region 16, a reverse taper region18, a barrel region 20, and an insertion tip region 22. As usedthroughout the present disclosure, the terms “section” and “region” areinterchangeable. The term “main barrel section” is interchangeable with“barrel region”, the term “finger grip section” is interchangeable with“grip region”, the term “reverse taper section” is interchangeable with“reverse taper region”, as are statements similar to these.

Grip region 16 is bound by a forward edge ridge 24 and a rearward edgeridge 26. Forward edge ridge 24 provides a firm grip surface duringinsertion of applicator 10 into the vaginal vault. Rearward edge ridge26 provides a firm grip surface during expulsion of the pledget (notshown) and during removal of applicator 10 from the body. Forward andrearward edge ridges 24, 26 are about 6 mm to about 22 mm in diameter,e.g., about 11 mm to about 17 mm in diameter, and in one embodiment,about 14 mm.

A grip region 16 is formed between forward edge ridge 24 and rearwardedge ridge 26. To ensure an adequate area to accept a user's finger orfingers, forward edge ridge 24 and rearward edge ridge 26 are spacedabout 13 mm to about 40 mm apart, e.g., about 17 mm to about 21 mmapart, and in one embodiment about 19 mm. Grip region 16 may be concave,convex, flat, or any combinations thereof, typically region 16 isconcave, which conforms to the contour of a user's finger. The maximumdiameter of grip region 16 is preferably slightly less than the diameterof edge ridges 24, 26. Preferably, grip region 16 has a maximum tominimum diameter ratio of about 1.10 to about 1.75, with a morepreferred ratio of about 1.25 to about 1.35.

Grip region 16 may also include one or more gripping structures toimprove grippability of applicator 10, for example, one or more andpreferably two or more, embossments, protuberances, slits, grooves,louvers, perforations, lances, abrasive medias, high wet coefficient offriction materials, pressure sensitive adhesives, or any combinationsthereof. In addition, gripping structures 46 may be formed in any shape,including, for example, arc, circle, concave, cone, convex, diamond,line, oval, polygon, rectangle, rib, square, triangle, or anycombinations thereof.

The maximum diameter 34 of applicator barrel 20 occurs at the forwardend of reverse taper section 18. Reverse taper is meant to include ataper in the reverse direction, i.e. in a direction away from theinsertion tip end 36 of applicator 10, but not necessarily the samedimensional taper as main body section 20. The diameter of reverse tapersection 18 tapers down toward forward edge ridge 24, where the diameteris equal to or slightly less than the diameter of forward edge ridge 24.This taper may be linear or curvilinear.

Maximum diameter 34 of barrel 20 exerts a slightly greater pressure thanthe smaller diameter portions of the barrel 20 on the vaginal opening.Thus, the location of maximum diameter 34 along the length of barrel 20is a critical aspect of this particular embodiment as it provides asensually perceivable way of signaling or indicating to a user thatapplicator 10 has been inserted to the correct depth. The location ofmaximum diameter 34 on barrel 20 is about 32 mm to about 54 mm in theaxial direction of barrel 20 from forward end 36 of insertion tip 22.Preferably maximum diameter 34 is located about 40 mm to about 50 mm,and more preferably about 44 mm in the axial direction of barrel 20 fromforward end 36 of insertion tip 22.

Barrel region 14 is joined to reverse taper region 18 where maximumdiameter 34 of barrel 20 is located. Barrel region 14 tapers towardinsertion tip section 22 in either a linear or curvilinear fashion sothat its smallest diameter occurs where barrel region 14 meets insertiontip region 22. The ratio of maximum diameter 34 to the diameter at theforward end 38 of barrel region 14 is about 1.1 to about 1.5, and morepreferably about 1.2 to about 13. This tapering of barrel region 14facilitates insertion comfort by gradually parting the vulva-vaginalchannel over a longer length than that of only insertion tip region 22.

Insertion tip region 22 begins where there is a substantial change inthe curvature of the forward portion of the barrel that is where thepledget 49 enclosing petals 40 are formed. In applicator designs whereno petals are used, insertion tip region 22 is the forward edge of thebarrel region 20 of barrel 14. The preferred insertion tip region 22 isthe petal type with a curvature that approximates an elliptical orhyperbolic curve. Preferably, insertion tip 22 has about 2 to about 12petals, and more preferably about 3 to about 8 petals. The ratio of themaximum diameter of insertion tip section 22, which occurs at the planewhere its rearward edge meets forward end 38 of main body section 20, tothe total axial length of the insertion tip section along a center axis11 of applicator 10, is about 0.9 to about 1.8, and more preferablyabout 1.1 to about 1.3.

It should be understood that while tampon applicator barrel 14 of FIGS.4 and 4 a are depicted as having four sections, namely a grip region, areverse taper region, a barrel region, and an insertion tip region, thetampon applicator barrel can include a reverse taper region and at leastone additional section selected from a grip region, a barrel region, aninsertion tip region, or any combinations thereof.

The interior wall of barrel 14 that houses the pledget may have the samebasic sidewall shape as its exterior wall. However, molding such acomplicated interior wall requires a complex manufacturing process.Alternately, the interior wall can be practically straight walled (aslight taper may be required for tooling release) while the exteriorwall has the sectional shapes discussed before, thus simplifying themolding process.

Referring to FIGS. 2 and 3, barrel 14 has a finger grip end 42. Plunger12 telescopically fits into the finger grip end 42 of barrel 14. Plunger12 has a diameter slightly smaller than the smallest diameter of gripregion 16 so that plunger 12 telescopically fits throughout the interiorof barrel 14. In one embodiment of the present plunger 12 has a diameterabout 4 mm to about 18 mm, e.g., plunger 12 has a diameter about 5 mm toabout 9 mm, e.g., about 7 mm.

Plunger 12 has a first flare 32 at its distal end and a second flare orretaining structure 48 at its opposite barrel end 52. Grip region 16 hasa plunger receiving end 30. Plunger receiving end 30 of grip region 16has a chamber 44 to receive first flare 32 of plunger 12 during pledgetexpulsion. This permits shortening the length of the section of plunger12 that protrudes from barrel 14 since all of the protruded length isavailable for the telescopic action. This in turns results in a moreergonomic applicator.

First flare 32 has a maximum diameter about 6 mm to about 22 mm.Preferably the maximum diameter is about 12 mm to about 16 mm, withabout 13 mm being the most preferred maximum diameter, in order toprovide a secure area for a user's fingertip during pledget expulsion.The rearward end of first flare 32 may be flat, concave, or convex.Preferably, it is concave to provide a secure area for the fingertip.

Second flare 48 has a maximum diameter about 5 mm to about 20 mm.Preferably the maximum diameter is about 11 mm to about 14 mm, withabout 13 mm being the most preferred maximum diameter, in order toprevent separation from barrel 14.

Although it might be implied that the cross-sectional shape of plunger12 and barrel 14 is circular, due to the use of the term ‘diameter’, itshould be understood that the cross-sectional shape can be non-circular,such as oval or polygonal. Furthermore, the cross-sectional shape canvary along the length of both plunger 12 and barrel 14. For example, acircular plunger with a polygonal finger grip and an oval main body maybe formed.

The polymer molding composition of the invention can be used in thepreparation of either plunger 12 and/or barrel 14.

FIGS. 4 and 4A are schematic representations of a tampon assemblycomprising a plunger 12, a barrel 20 that tapers and becomes more narrowat or towards the insertion tip region, and a pledget 49 comprising awithdrawal cord 51, which pledget 49 in this case is also tapered andsupports the petals 40.

Plunger 16 is useable to expel pledget 49 from barrel 14. Plunger 16 isslideably disposed in barrel 14 at second end 22. Pledget 49 is expelledthrough first end 20 through the movement of plunger 16 in the directionof arrow 32. As plunger 16 moves in the direction of arrow 32, theplunger can urge pledget 49 into petals 26 until the petals open alongslits 29 and the pledget is expelled from barrel 14 through insertiontip 24.

Insertion tip region 22 is, preferably, tapered or elliptical in shape.Specifically, insertion tip region has a linear or non-linear taper fromthe insertion tip end 36 to the opposite end adjacent the barrel region.

The taper of insertion tip 22 is defined as a ratio of the maximumradial dimension of insertion tip 22, divided by length of the insertiontip region 22. In one embodiment of the present disclosure, insertiontip 22 has a taper ratio of more than about 0.3 to less than 1.0. Inanother embodiment, insertion tip 22 has a taper ratio of more thanabout 0.4 to less than about 0.8. In yet another embodiment, insertiontip 22 has a taper ratio of about 0.4 to about 0.5. An insertion tip 22that tapers gently towards the insertion tip end 36 is preferred forinsertion ease, insertion comfort.

Pledget 49 is shaped to support insertion tip 22.

Pledget 49 supports a portion of inner surface area of the applicatorbarrel 14. The tip end of the pledget 49, most preferably, has a shapeclosely matching a shape of insertion tip 22 to provide proper supportfor petals 26. The taper ratio of the pledget tip end, preferably,matches the shape of insertion tip 22.

Advantageously, shaped pledget 13 prevents forces on insertion tip 22applied during insertion of barrel region 14 into the body fromcollapsing petals 40 inward towards the pledget. Further, shaped pledget49 enables the petals 40 to be made thinner to decrease the expulsionforce while still mitigating the collapse or deflection of petals 40. Inone embodiment of the present disclosure the petals 40 have a thicknessbetween about 0.005 inches (0.127 mm) to about 0.03 inches (0.762 mm),and any range there between. In a preferred embodiment, the petals havea thickness between about 0.006 inches (0.1 mm) to about 0.013 inches(0.330 mm). In another preferred embodiment, the petals have a thicknessbetween about 0.008 (0.203 mm) inches to about 0.011 inches (0.279 mm).

Some specific embodiments of the invention include, for example, anapplicator comprising the polymer composition of the invention, a tamponapplicator comprising said barrel, or a tampon assembly comprising saidbarrel, which barrel comprises a wall forming a tube with a center axis11 therethrough and with a hollow interior volume, the tube having afirst barrel end and a second barrel end opposite the first barrel endthat is a free end, the first barrel end and the second barrel end forma length there between that corresponds to the length of the center axis11, the tube increasing in diameter along the length of the tube from afirst diameter to a second diameter that forms a main body section, anddecreasing in diameter along the length of the tube from the seconddiameter to a third diameter that forms a reverse taper section, whereinthe center axis 11 is substantially straight throughout the extant ofthe tube, wherein the second diameter is a maximum diameter of the tube.In many embodiments the first diameter of the barrel is connected to aninsertion tip section. Typically the diameter of the tube decreases indiameter along the length of the tube from the first diameter to thefirst barrel end in the insertion tip section and the insertion tipsection generally has a plurality of petals formed by slits or cuts inthe tube.

In some embodiments the third diameter of the barrel connects directlyto a finger grip section, wherein the finger grip section has a forwardedge ridge adjacent the reverse taper section, wherein the finger gripsection has a rearward edge ridge at the second barrel end, and whereinthe forward edge ridge and the rearward edge ridge has a fingeraccepting region there between, and in some embodiments the finger gripsection has a length from the third diameter to a fourth diameter, andwherein the tube decreases in diameter from the third diameter to thefourth diameter.

In some embodiments the tube increases in diameter along the length ofthe tube from the fourth diameter to a fifth diameter and in someembodiments the fifth diameter is at the second barrel end, wherein thesecond barrel end has an opening into the interior volume for receipt ofa plunger.

In the tampon applicator 10 or tampon assembly the plunger 12 typicallyhas a first plunger end 52 and a second plunger end 32, wherein thefirst plunger end 52 is within the interior volume and the secondplunger end 32 has a shape that is complimentary to the shape of thegrip region 16 between the fourth diameter and the fifth diameter. Inthe tampon assembly comprising the barrel above, the barrel has aninterior wall that houses a pledget opposite an exterior wall and thepledget 49 is shaped to have a tapered end that supports at least aportion of the petals 40.

In particular embodiments of the above barrel, tampon applicator ortampon assembly, the barrel increases in translucency at the insertiontip region.

The features found in the figures and specific embodiments discussedabove represent specific aspects of particular embodiments of articlesprepared using the polymer molding composition of the invention, but themolded articles of the invention are certainly not limited to only theseaspects or embodiments.

What is claimed is:
 1. A polymer molding composition, comprising, basedon the total weight of the polymer composition: from about 95 to about99.8 wt. % of an organic polymer, from about 0.15 to 0.33 wt. %, of apearlescent pigment comprising mica, from about 0.002 to about 0.1 wt. %of a colorant other than a pearlescent pigment comprising mica, fromabout 0.05 to about 1.0 wt. % of a lubricant comprising a fatty acidamide and from 0 to about 4.8 wt. % other additives.
 2. The polymermolding composition according to claim 1 wherein the pearlescent pigmentcomprising mica comprises a mica particle coated with one or morelayers, wherein at least one layer comprises titanium dioxide.
 3. Thepolymer molding composition according to claim 1 or 2 wherein thelubricant comprises erucamide, oleamide, stearamide, stearyl erucamideor bis-erucamide.
 4. The polymer molding composition according to claim2 comprising from about 0.005 to about 0.07 wt. % of a colorant otherthan a pearlescent pigment comprising mica.
 5. The polymer moldingcomposition according to claim 1, comprising from about 0.05 to about4.8 wt. % other additives comprising one or more additive selected fromthe group consisting of plasticizers, compatibilizers, flow modifiers,antioxidants, antistatic agents, fillers, reinforcements, surfactants,light/UV stabilizers, thermal stabilizers, impact modifiers, processingaids, other lubricants, flame retardants, biocides, antiozonants,blowing agents and anti-foaming agents.
 6. The polymer moldingcomposition according to claim 1, wherein the organic polymer comprisesone or more polyolefin polymer or copolymer, polyester, polyamide,polystyrene, polyvinyl chloride, polyacrylate, polymethacrylate,polyvinyl alcohol, polylactic acid, and/or moldable starch.
 7. Thepolymer molding composition according to claim 6 wherein the organicpolymer comprises polyethylene, low density polyethylene, high densitypolyethylene, near low density polyethylene, polypropylene, copolymerscomprised of ethylene, styrene, isoprene or butadiene monomers.
 8. Atampon applicator assembly, comprising, based on the total weight of apolymer composition: from about 95 to about 99.8 wt, % of an organicpolymer, from about 0.05 to 0.4 wt. %, of a pearlescent pigmentcomprising mica, from about 0.002 to about 0.1 wt. % of a colorant otherthan a pearlescent pigment comprising mica, from about 0.05 to about 1.0wt, % of a lubricant comprising a fatty acid amide and from 0 to about4.8 wt. % other additives; wherein the tampon applicator assembly has alength and an insertion tip region adjacent a barrel region, wherein thetampon applicator has variable translucency in the insertion tip region.9. The tampon applicator according to claim 8, wherein the insertion tipregion decreases in translucency as it approaches the barrel region. 10.The tampon applicator assembly according to claim 8, wherein the tamponapplicator assembly further comprises a plunger.
 11. The tamponapplicator assembly according to claim 10, wherein the plunger comprisesa first plunger segment and a second plunger segment, wherein at leastone of the first plunger segment and the second plunger segment issubstantially translucent or has variable translucency.
 12. The tamponapplicator assembly according to claim 11, wherein at least a portion ofa tampon pledget is visible through the tampon applicator assembly.